Wire break-off mechanism



Feb. 7, 1961 c. L. MILLER ETAL WIRE BREAK-OFF MECHANISM 2 Sheets-Sheet 1 Filed May 6, 1959 INVENTORS Cfiarles L. Miler Gall K Weaver ZRNEY Feb. 7, 1961 Filed May 6, 1959 c. MILLER ETAL 2,970,731 WIRE BREAK-OFF MECHANISM 2 Sheets-Sheet 2 INVENTORS jazrzas Z. .MZZZer ATTORNEY Gail K Wavar United States WIRE BREAK-OFF MECHANISM iCharles L. Miller, Clinton, and Gail -K. Weaver, Rebersburg, Pa., assignors toSylvania Electric Products Inc., =.a.corporation.of Delaware --Filed Mayo, -1959,-Ser. No. 8115342 9 Claims. -(Cl.,225--93) This invention relates -.to .;wire .abreak-oif mechanism. In the manufacture of some tYPBStOfjfilCCIIOH tubes,

it isnecessaryto provide a.;stcm;to'form; part'of thetube and :comprisedof adisc-likeglasstube base-traversed by tanumber :oflead-in .wires, these wires, in the completed lid-be being connected to ElCCIIOCltBSzWllhll'l the tubeand extending exterio-rly of the tube to form exterior electrodeszto beplugged into a socket. Where the number .;of:.such..lead-in wires is gsmall and therefore the wires mifordinsufiicient support for parts withinthe tube, it-has "been customary topembed Within the stem additional :wires or so calleddummy leads to support'the parts and :;these leads in the completedtubedo not extend exteriorly .-.ofithe-tube.

:'Inone form ofdummy lead, disclosed inthe Cresswell and Schneiring Patent 2,892,008 dated June-23, 1959, the

the portions .of the lead-in wires which aretobe electrode connected.

:It is: an object of this invention to provide a device -easily :fitted within an existing :stem processing machine ato automaticallysnapoif the nndesiredwire portion of a:lead-in:wire-as-the stem is fedto said machine.

It is a further object of the invention to provide a mechanism which will automatically vsnapoffrthe excess wireof a-dumrny lead-in wire as a stem provided with such dummy lead-in wireis fed into the stem processing machine.

These-and other-objects will become apparent after reading the following specification when taken in conjunction with the accompanying'drawing inwhich:

Eig. l'is afra-gmentary view of astem inserting mechjanismillustrating a stem with its tubulation ready to be graspedfor transfer from a cradle on a conveyor to a chuck of the stem processing machine.

Fig. .2 is a similar view but with the tubulation of the stem p artially inserted into the chuck and the lead-in wires close to the chuck.

Fig. 3 is a similar view showing-the stem fully inserted in the chuck with two wires or dummy leads snapped ofi.

, Fig. 4 is a diametrical, cross section through the chuck.

Fig. 5 is an exploded View of the chuck.

Fig. 6 showsa form of wire breaker to be inserted in the chuck.

- Fig. 7 shows a modified form of the breaker.

Fig.8 is a fragmentary section through astem showing a through lead-in wire embedded in the stem.

Fig. 9 is a similar section showing a dummylead traversing' the base of the stem prior to snapping off of the portion'of the lead below the glass base.

atent 0 is shown a cradle for supporting a stem, the cradle being one of a number on a chain conveyor which receives stems from a stemforming machine. At 22 is shown a chuck for receiving the stem, this chuck being mounted on a conveyor to carry .the stems to lead-in cutting and bendingv mechanism, while at 24 is shown in diagram- .maticform a transferdevice for transferring the stem :from agcradle, which, as shown in Fig. 1, has been tilted "to horizontal position, to the chuck.

The mechanism .so far-described is for the purpose of affording a background for. applicants invention, and,'in and of itself, forms ;no part of. the invention. Only so muchbf the structure indicated generically as 20, 22 and .24 .will be described as will be necessary to understand the invention. Inithe prior art, the conveyors supporting the equally spaced cradles and correspondingly spaced chucks are moved intermittently so that as a cradle reaches a position opposite a chuck, the transfer device 24 will grasp the stern and transfer it to the chuck.

.Ihe cradle 20 comprises a head 26 having an arcuate platform 27, Fig. 1, for supporting the ends of lead-in wires of the base ordisc 28 of the'stem 29 and a saddle :30. spaced from the head'for supporting the tubulation -32 on the stem, this tubulation being utilized in the later manufacture of the tube as a means to enable evacuation -.of the tube prior to the tubulation being sealedclose to cthe base of the tube and tipped off thereat. The stem also Qincludestwo types of wires, knownas 'Dumet wires, one

type of wire having two thickportions 36 and,38- partially' within the glass base and connected by.a copper clad thinner portion 40 wholly embedded in the glass .-base. The other or dummy type of wire 42 is of similar construction but the joint between the copper'clad-section .44 and the thicker portion 46 is at the surface of the glass base so that a lateral thrust on the portion 46 will break the wire at the surface, all asexplained at greater length in the patent above referred to. The cradle is brought to itshorizontal position bya tilt mechanism, not shown, as the conveyor carrying the cradle indexes to the transfer position.

Each chuck 22 comprises a'body 48 with upper and lower arms 50 and 52, with thearm 50 of one chuck articulated to the arm 52 of .an adjoining chuck and both overlapping arms articulated'to the chain conveyor supporting'thebodiesby pinspassing through vertical apertures 54 in the arms.

The body has a cylindrical horizontal opening 56 with a plane surface 58. at the left of Fig. 4 against which rests a collar. 60. The collar 60 has fixed thereto diametrica-l locating pins 62 seated in holes 63 in thebody 48 and isheld tothe body by a screw 49 passing through a notch 51 in the collar and threaded into thebody. The collar also has a flange 64 overlying the vertical front face of the body and in this flange are three apertures 66 for seating three coiled compression springs 68 which thrust against a chuck ring 70,, the outer ends of the springs being located in recesses 72in the ring. The collar has a second pin 74 on the sideof the collar opposite to, the side carrying the pins 62,..the

,pin 74 slidably snugly engaged within an aperture in the chuck ring to guide the ring in its to be described move ment toward and from the collar .60. The ring .has an internal bevelled wall 76' to form a wedge surface...for

through'its head corresponding in position and number to the total number of lead-in wires in the glass base and for each perforation there is a communicating seat 88 for its ball 78. The shank 84 is threaded and provided with a nut 90 which bearsagainst a spacer flange cylinder 92 within the chuck body, the spacer cylinderib'eing interposed between the nut and the collar 60. :The chuck stem 80a-lso has a central through opening 94 for accommodating the exhaust tubulation 32.0f the'glass stem when thelead-in wires, are thrust into the chuck. The balls 78 normally occlude the perforations 86 by reason of the springs 68 pressing the inclined wall 76 of the chuck ring 70 against the balls, the outward motion of the ring being limited by the outer face of, the ring engaging a flange 96 on the chuck stem. The head of the chuck stem on its under faces bears against the collar 60. Thus the chuck stem is held against movement by reason of its being clamped against collar 60 by nut 90 and spacer cylinder 92. When the chuck ring 70 is pressed toward the collar 60, the balls 78 are free to move and stem lead-in wires are then easily insertible into the perforations 86. When the ring is released to the action of its spring 68, the lead-in wires are clamped in the perforations by reason of the thrust action of the balls 78.

Those balls which would otherwise be in line with the dummy leads are removed, and inserted into the thus otherwise unobstructed perforations 86 are the rods 98 of breakers 100. The breakers shown in detail in Fig. 6 each comprises the rigid rod 98 and a metallic block 102 with a positioning lip 103 engaging the outer edge of the flange 96 to prevent rotation of the breaker in the perforation. The rod is held within the block in any convenient fashion as by a set screw 104. The block is generally a modified parallelepiped with the rod extending from an unmodified face of the block. The opposite face of the block is modified to have a hard surfaced bevelled face 106 adapted to be engaged by the end of a dummy lead wire so that as the wire is thrust toward the block in a direction parallel to the rod 98, the end of the dummy lead wire will engage the bevelled face and it will be deflected and finally broken off at the juncture of the dummy lead wire with the surface of the base of the glass stem. The rod 98 of the breaker is held in the perforation in the chuck stem by a screw 108 threaded into the collar 60 and engaging the rod.

In the modification of Fig. 7, the rod 98 of Fig. 6 is replaced by a bent rod 110 whose resiliency is sufficient to maintain the block in the perforation in the chuck stem without the use of a screw. The screw to hold the block is preferred however since it affords better securement of the breaker within the chuck stem.

To shift the chuck ring 70, any conventional means is employed, as a pivoted fork 112 whose pins 114 engage the face of the ring and move the ring concomitantly with the shifting of the transfer device to insert the glass stem lead-in wires and exhaust tubulation into the chuck. This fork is oscillated by any conventional means in timed relationship with conveyor indexing.

The transfer means is also conventional and comprises a transfer plate 120 on which is pivoted a pair of arms 122, as by pivot pins 124, the upper ends of the arms being shown spread apart by the action of a compression spring 126. The lower ends of the arms are formed into arcuate jaws 128 adapted to grasp the circular base of the stem when the stem is tilted to horizontal position by swing of the cradle 20. The jaws are separated by a wedge block 130 normally retracted to an up position by a spring 132 afiixed thereto and cammed down by a spring retracted finger 134 pivotally mounted in a transfer bar 136. The finger is operated by a thrust rod 138 slidable in the thrust bar 136, the bar 138 having a cam at its end to engage the finger to depress it against the action of its spring. The transfer bar is operated in any suitable fashion, as by cam mechanism timed with conveyor indexing movement-to reciprocate the plate 120 and jaws 128 between the two conveyors, and the thrust rod is also suitably operated by cam mechanism similarly coordinated with the indexing movement of the conveyors.

As the transfer device 24 brings the stem toward the chuck body 48, the fork 112 will depress the chuck ring 70 to facilitate entrance of the leads into the perforations of the chuck. Just prior to the movement of the transfer device toward the breaker, the cradle will tilt downwardly. Then as the transfer device operates the dummy leads will strike the inclined surfaces 106 of the breakers, will be deflected and finally broken off. The fork 112 will now release the collar 60, the transfer arm will then release the glass stem and move to pick up another glass stem, as a cradle supporting the next stem moves from a vertical to horizontal position. The chain supporting the chuck bodies indexes to present a new chuck body with breakers therein to the next oncoming stem transported by the transfer device 24.

What is claimed is:

1. Wire break off mechanism for breaking away excess wire from a dummy wire traversing a stem, said stem being comprised of a base with lead-in wires passing through the base and perpendicular to a surface thereof and with at least one said dummy wire, said dummy wire being weakened at that surface, said mechanism including a chuck having a face with unobstructed apertures therethrough to receive said lead-in wires, said chuck carrying a breaker, said breaker having a face inclined to the face of the chuck occluding one of said apertures and in line with the on-coming dummy wire as the lead-in wires of the stem are fed into the apertures of the chuck, to bend and break off said dummy wire at said weakened portion.

2. Wire break off mechanism for breaking away excess wire from a dummy wire traversing a stem, said stem being comprised of a base with lead-in wires passing through the base and perpendicular to a surface thereof and with at least one said dummy wire, said dummy wire being weakened at that surface, said mechanism including a chuck having a face with unobstructed apertures therethrough to receive said lead-in wires, said chuck being further provided with a breaker, said breaker having a face inclined to the face of the chuck occluding one of the apertures in the face and a stem held within said occluded aperture of the chuck and in line with the on-coming dummy wire as the lead-in wires of the stem are fed into the apertures of the chuck, to bend and break off said dummy wire at said weakened portion.

3. Wire break off mechanism for breaking away excess wire from a dummy wire traversing a stem, said stem being comprised of a base with lead-in wires passing through the base and perpendicular to a surface thereof and with at least on said dummy wire, said dummy wire being weakened at that surface, said mechanism including a chuck having a face with unobstructed apertures therethrough to receive said lead-in wires, said chuck being further provided with a breaker, said breaker having a face inclined to the face of the chuck and occluding one of said apertures and a bent rod held within said occluded aperture of the chuck, said inclined face being in line with the on-coming dummy wire as the lead-in wires of the stem are fed into the apertures of the chuck, to bend and break off said dummy wire at said weakened portion.

4. Wire break off mechanism for breaking away excess wire from a dummy wire traversing a stem, said stem being comprised of a base with lead-in wires passing through the base and perpendicular to a surface thereof and with at least one said dummy wire, said dummy wire being weakened at that surface, said mechanism including a chuck having a face with unobstructed apertures therethrough to receive said lead-in wires, said chuck being further provided with a breaker, said breaker comprising a parallelpiped modified to have a bevelled face and a rod extending perpendicularly from the face opposed to the bevelled face, said rodextending in and held in said chuck and said bevelled face being in line with the oil-coming dummy wire as the leadin wires of the stem are isd into the apertures of the chuck, to bend and break ofi said dummy wire at said weakened portion.

5. Wire break off mechanism for breaking away excess wire from a dummy wire traversing a stem, said stem being comprised of a base with leaddn wires passing through the base and perpendicular to a surface thereof and with at least one said dummy wire, said dummy wire being weakened at that surface, said mechanism including a chuck having a face with unobstructed apertures therethrough spaced about the face near the periphery thereof to receive said lead-in wires, said chuck carrying a breaker, said breaker having a face occluding one of said apertures and another face inclined to the face of the breaker occluding said one of said apertures and in line with the on-coming dummy wire as the lead-in wires of the stem are fed into the apertures of the chuck, to bend and break off said dummy wire at said weakened portion.

6. Wire break off mechanism for breaking away excess wire from a dummy wire traversing a stem, said stem being comprised of a base with lead-in wires passing through the base and perpendicular to a surface thereof and with at least one said dummy wire, said dummy wire being weakened at that surface, said mechanism including a chuck having a face with unobstructed apertures therethrough adjacent the boundary of the face to receive said lead-in wires, said chuck being further provided with a breaker, said breaker having a face inclined to the face of the chuck occluding one of the apertures in said chuck face and a rod forming part of the breaker held within said occluded aperture of the chuck with the breaker in line with the on-coming dummy wire as the lead-in wires of the stem are fed into the apertures of the chuck, to bend and break off said dummy wire at said weakened portion.

7. Wire break off mechanism for breaking away excess wire from a dummy wire traversing a stem, said stem being comprised of a base with lead-in wires passing through the base and perpendicular to a surface thereof and with at least one said dummy wire, said dummy Wire being weakened at that surface, said mechanism including a chuck having a face with unobstructed apertures therethrough to receive said lead-inwires, said chuck carrying a breaker, said breaker having a face inclined to the face of the chuck and in line with the oncoming dummy wire as the lead-in wires of the stem are fed into the apertures of the chuck, to bend and break off said dummy wire at said weakened portion, said breaker being further provided with a lip engaging an edge portion of the chuck to prevent rotation of the breaker in the aperture.

8. A breaker for insertion into a chuck, said breaker comprising a metallic block of generally parallelpiped form modified to have one face bevelled, a rod attached to the face of the parallelepiped opposite to the bevelled face and perpendicular to said opposite face, and a lip on the breaker parallel to and spaced from the rod, said lip extending in the same direction as the rod.

9. in combination, a chuck having unobstructed apertures, a breaker held by said chuck, said breaker comprising a metallic block of generally parallelepiped form with one face modified to have its face bevelled, and a resilient rod attached to the face of the modified parallelepiped opposite to the bevelled face, said rod being bent intermediate its length so that the free portion of the rod forms an obtuse angle with the block attached portion of the rod, said rod being inserted in one of said apertures to resiliently engage the inside wall of the aperture to thereby hold the breaker to the chuck.

References Qited in the file of this patent UNiTED STATES PATENTS 832,671 Hist Oct. 9, 1906 1,496,740 Johnson Feb. 14, 1922 1,477,582 Miller et a1. Dec. 18, 1923 1,516,877 Anekee Nov. 25, 1924 2,537,464- l-lolm-berg Jan. 9, 1951 FOREIGN PATENTS 211,523 Switzerland Dec. 2, 1940 

